The present invention relates to an imaging device which includes an optical zoom function with, a zoom lens and a digital zoom function by an image processing.
An imaging device such as a compact digital still camera having a simple video shooting is now widespread.
Further, an imaging device with an optical zoom during a video shooting or to perform both an optical zoom and a digital zoom has been increasing. The optical system of such an imaging device often has a minimum object distance of several centimeters at a wide angle and several ten centimeters at telephoto.
Further, a product having a function to change a minimum object distance between a macro mode and a normal shooting mode is available.
If a user starts shooting a subject at a certain distance far from the minimum object distance at a certain angle of view and zooms the subject towards telephoto at an angle of view shorter than the minimum object distance, captured images will be all blurred and out of focus.
In view of the above problem, Japanese Patent Application Publication No. 2009-224882 discloses an imaging device which displays a minimum object distance on a screen and informs a user that a zooming from the minimum object distance to telephoto is unfeasible, for example. However, it cannot meet users' desire for zooming a subject in focus without blurs.
For another example, Japanese Patent Application No. H03-15808 discloses an imaging device which stops optical zoom when a distance between a subject and the device reaches the minimum object distance to avoid out-of-focus situation. However, it cannot meet users' desire for zooming a subject in focus, either.
Meanwhile, in recent years the number of pixels of an image sensor incorporated in a digital still camera has been increased to be larger than that of a high-definition broadcast. Therefore, the use of a virtual zoom or digital zoom by trimming during video shooting is unlikely to degrade visual quality of an image due to insufficient resolution.
Therefore, irrespective of the optical zoom's reaching the telephoto end, the use of both digital zoom and optical zoom from a certain focal length can improve users' convenience since it enables generation of zoomed images in accordance with a photographic situation.